A meta-analysis of the prevalence of lower limb asymptomatic bone stress injuries in athletes and military personnel
Citation:Mills, R. (2014). A meta-analysis of the prevalence of lower limb asymptomatic bone stress injuries in athletes and military personnel. An unpublished thesis submitted in partial fulfilment of the requirements for the degree of a Masters in Health Science.
Permanent link to Research Bank record:http://hdl.handle.net/10652/2855
Bone stress injuries (BSI) appear to be widely accepted throughout the medical and sports world, although the importance of asymptomatic injuries remain unclear and their clinical relevance questionable. OBJECTIVES: To determine the prevalence of asymptomatic BSI in the lower limb using a systematic review of the published literature, secondly to identify any differences between athletic and military populations in the prevalence of lower limb asymptomatic BSI and finally to highlight the locations in the lower limb with the highest prevalence. SUBJECTS AND METHODS: An electronic database search was conducted using two databases: PubMed and Medline. Two observers independently systematically reviewed these data, assessing the studies against pre-determined criteria. The number of subjects BSI, location and imaging modalities were subsequently extracted from the selected studies. A mixed model analysis with random effect was used to calculate prevalence rates, confidence intervals and p values. RESULTS: The overall prevalence rate of asymptomatic BSI was 27/100 from all studies (military, athletes and civilian). Athletes had a significantly higher prevalence of asymptomatic BSI 75/100 than military personnel 28/100 (p= 0.0065), although the overall rates of BSI were not significantly different between these populations. The tibia was the most prevalent site for both symptomatic and asymptomatic BSI with 9.3 and 7.7 per 100 patients respectively and there was a significant difference between symptomatic (0.3/100) and asymptomatic (28/100) BSI in the tarsal bones (p=0.049) and in the fibula, 2.4/100 symptomatic and 6.8/100 asymptomatic (p=0.024). CONCLUSION: Although a number of studies identified the existence of asymptomatic BSI, most failed to provide adequate follow-up in order for their clinical significance to be properly assessed and thus it is difficult to postulate the clinical significance of the 27/100 prevalence rate given a lack of empirical evidence. The higher prevalence of asymptomatic BSI in athletes is probably multifactorial with training history, motivation, fitness levels and sampling bias all possibly explaining some or all of this higher rate.